银屑病患者皮损和外周血中CD8α+α+ T细胞的研究

目的 观察银屑病患者皮损和外周血中CD8α+α+ T细胞的分布和比例，探讨其在银屑病发病中的作用。 方法 采用免疫荧光技术观察5例进展期寻常性银屑病患者和5例健康人皮肤中CD8α+α+ T细胞的分布，流式细胞仪分别检测10例进展期寻常性银屑病患者和8例健康人外周血中CD8α+α+ T细胞比例及干扰素γ（IFN-γ）和肿瘤坏死因子α（TNF-α）的表达。采用Graphpad Prism统计软件对实验组和对照组各数据进行t检验。 结果 在5例银屑病患者皮损真皮浅层均可见以CD8α+α+ T细胞为主的浸润，未见明显的CD8α+β+ T细胞浸润；而5例健康人皮肤中均未见CD8α+α+ T细胞和CD8α+β+ T细胞浸润。流式细胞仪检测，8例健康人外周血中CD8α+α+ T细胞比例为9.12% ± 4.80%，10例银屑病患者组为26.47% ± 12.99%，银屑病患者组明显高于对照组，两组比较，t = 3.96，P ＜ 0.001。在银屑病患者外周血CD8α+α+ T细胞中分泌IFN-γ和TNF-α的细胞比例分别为47.36% ± 19.38%和54.14% ± 21.14%，健康对照组分别为13.44% ± 9.21%和34.03% ± 17.22%，两组差异均有统计学意义（t值分别为4.54和2.17，P值分别 ＜ 0.001和 ＜ 0.05）。 结论 银屑病患者皮损和外周血中存在CD8α+α+ T细胞的分布和比例增多，CD8α+α+ T细胞可能是参与银屑病发病的主要CD8+ T细胞亚群。

CD8α+α+ T cells in lesions and peripheral blood of patients with psoriasis

Sun Xiuwen, Li Bing, Zhang Weigang, Dang Erle, Jin Liang, Wang Gang. Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi′an 710032, China Corresponding author: Wang Gang, Email: xjwgang@fmmu.edu.cn 【Abstract】 Objective To investigate the distribution and proportion of CD8α+α+ T cells in lesions and peripheral blood of patients with psoriasis, and to assess their roles in the pathogenesis of psoriasis. Methods An immunofluorescence assay was performed to observe the distribution of CD8α+α+ T cells in lesions of 5 patients with progressive psoriasis vulgaris and normal skin of 5 healthy human controls. Flow cytometry was conducted to determine the proportion of CD8α+α+ T cells, and to measure the expressions of interferon （IFN）-γ and tumor necrosis factor （TNF）-α in peripheral blood from 10 patients with progressive psoriasis vulgaris and 8 healthy human controls. Statistical analysis was carried out by t test with GraphPad Prism software. Results A massive infiltrate mainly composed of CD8α+α+ T cells but not CD8α+β+ T cells was observed in the upper dermis of lesions from the 5 patients with psoriasis, while there was no infiltrate of CD8α+β+ or CD8α+α+ T cells in the normal skin of 5 healthy human controls. Flow cytometry revealed that the proportion of CD8α+α+ T cells was significantly higher in peripheral blood from 10 patients with psoriasis than in that from 8 healthy human controls （26.47% ± 12.99% vs. 9.12% ± 4.80%, t = 3.96, P < 0.001）. Significant differences were also noted between the psoriatic patients and healthy human controls in the percentage of cells secreting IFN-γ （47.36% ± 19.38% vs. 13.44% ± 9.21%, t = 4.54, P < 0.001） and cells secreting TNF-α （54.14% ± 21.14% vs. 34.03% ± 17.22%, t = 2.17, P < 0.05） in peripheral blood CD8α+α+ T cells. Conclusions Both the distribution and proportion of CD8α+α+ T cells are increased in lesions and peripheral blood from patients with psoriasis, suggesting that CD8α+α+ T cells may be the main subgroup of CD8+ T cells that contribute to the pathogenesis of psoriasis.